Nonfatal Firearm Injury and Firearm Mortality in High-risk Youths and Young Adults 25 Years After Detention

Key Points Question What are the incidence rates of nonfatal firearm injury and firearm mortality in youths who have been involved with the juvenile justice system? Findings This 25-year longitudinal cohort study (n = 1829) found that youths involved with the juvenile justice system had up to 23 times the rate of firearm mortality as the general population; rates varied by sex, race and ethnicity, and age. Sixteen years after detention, more than one-quarter of Black and Hispanic males had been injured or killed by firearms. Meaning These findings suggest that reducing firearm injury and mortality in high-risk youths and young adults requires a multidisciplinary approach involving legal professionals, health care professionals, educators, street outreach workers, and public health researchers.

This supplemental material has been provided by the authors to give readers additional information about their work.

Characteristics of the Cook County Juvenile Temporary Detention Center (CCJTDC)
No single site can represent the entire country because jurisdictions may have different options for diversion and different demographics. We chose the detention center in Cook County (which includes Chicago and surrounding suburbs) for three reasons: First, nationwide, most detained youth live in and are detained in urban areas. 1 Second, Cook County has the third largest Hispanic population in the United States. 2 Studying Hispanic youth is important because they are overrepresented in the justice systems. 3 Finally, the detention center's size (daily census of approximately 650 youth and intake of 20 youth per day) insured that enough participants would be available.
Consistent with detained youth nationwide, 4 nearly 90% of detainees at CCJTDC were male; most were Black and Hispanic youth. CCJTDC's population was 77.9% Black, 5.6% non-Hispanic White, 16.0% Hispanic, and 0.5% other racial or ethnic groups. 3 The age and offense distributions of CCJTDC detainees are also similar to detained youth nationwide.

Sampling and Procedures
Northwestern Juvenile Project (NJP) participants include 1829 male and female youth, 10 to 18 years old, randomly sampled from intake into the CCJTDC from November 20, 1995, through June 14, 1998. The sampling was stratified by sex, race and ethnicity (Black, non-Hispanic White, Hispanic, and "other" race and ethnicity), age (10-13 years or ≥14 years), and legal status (processed in juvenile or adult court) to obtain enough participants to examine key subgroups (e.g., females, Hispanics, younger persons). There were 13 strata, as listed below. There were too few female detainees of each race and ethnicity and detainees identified as "other" race and ethnicity to further stratify these groups. Detainees aged 10 to 13 years were not stratified by legal status because they were generally too young to be considered for transfer to adult court. A study liaison was scheduled to work every day (including weekends) throughout the study. Each day, the liaison randomly selected potential participants within strata. Detainees were classified in strata using information listed in the intake log. The liaison sampled from the strata in a preset order. If no participants were available for a stratum, the liaison sampled from the next stratum. If multiple detainees were available for a stratum, the liaison used a random number table and the last digit of the CCJTDC ID number to randomly sample potential participants from within the stratum. 5 The final sampling fractions for the strata ranged from 0.018 to 0.689.
All detainees who were awaiting the adjudication or disposition of their case were eligible to participate in the study. Among these, 2275 detainees were randomly selected; 4.2% (34 youth and 62 parents or guardians) refused to participate. There were no significant differences in refusal by sex, race and ethnicity, or age. Twenty-seven youth left the detention center before an interview could be scheduled; 312 left CCJTDC while we attempted to locate their caretakers for consent. Eleven others were excluded from the sample because they were unable to complete the interview. The final sample size was 1829 participants: 1172 male, 657 female; 1005 Black, 296 non-Hispanic White, 524 Hispanic, 4 "other" race and ethnicity; age range, 10 to 18 years (mean, 14.9 years; median, 15 years) (see eTable 1).
The most common offenses were violent crimes (55.4%), property crimes (43.5%), violation of probation or parole (36.4%), drug crimes (30.7%), and weapons crimes (13.5%). (Numbers sum to >100% because participants could be arrested for more than 1 charge.) Face-to-face structured interviews were conducted at the detention center in a private area, most within 2 days of intake. Participants were paid $25 for the 2-to 3-hour baseline interview.
We re-interviewed participants irrespective of where they lived: in the community (65%-69% of interviews); at correctional facilities (15%-29% of interviews); by telephone if they lived more than 2 hours away (4%-16% of interviews); or in a placement, such as a group home (<2% of interviews.) Participants were paid $50 for the 3-through 6-year follow-up interviews; $75 for the 8-through 13-year follow-up interviews; and $100 for the 14-through 16-year follow-up interviews, each lasting approximately 3 to 4 hours.

Youth Processed in Juvenile or Adult Court
Although most juvenile offenders are processed in juvenile court, all 50 states and the District of Columbia have legal mechanisms to try juveniles as adults in criminal court. 6,7 Transfers to adult criminal court typically result from: (1) judicial waiver on a case-by-case basis, [8][9][10] (2) automatic transfers based on the type of offense, criminal history, and age of the detainee, 8 and (3) prosecutorial direct-file mechanisms that allow prosecutors to determine when to file certain juvenile cases directly in adult criminal court. 8 The increased availability of legal mechanisms to process juveniles in adult criminal court is largely responsible for the 366% increase between 1983 and 1998 in the number of juveniles held in adult jails. 11 As of 2004, about 7% of the approximately 2 million arrests of youths eligible for processing in the juvenile justice system were cases in which the youth was transferred directly to adult criminal court. 4,12

Procedures for Obtaining Parental Consent for Minor Youth
For all interviews, participants signed either an assent form (if they were <18 years) or a consent form (if they were >18 years). The Northwestern University Institutional Review Board and the Centers for Disease Control and Prevention Institutional Review Board approved all study procedures and waived parental consent for persons younger than 18 years, consistent with federal regulations regarding research with minimal risk. 13 We nevertheless attempted to contact parents of minors to obtain their consent and to provide them with information on the study and used an independent participant advocate to represent the minors' interests. 13 Baseline Study liaisons tried to reach detainees' parents or guardians in 2 ways: first, they attempted to call them by telephone at least 3 times over 2 days. Second, they tried to obtain consent from the parents or guardians in person during visiting hours. A participant advocate acted on the child's behalf if the parents or guardians were not reachable. In the absence of a parent or guardian, the participant advocate protects the interests of the youth and determines that they are consenting voluntarily, understand the research procedure, and are not being coerced to participate. Consistent with federal regulations, we excluded detainees who did not wish to participate, even if their parents or guardians consented. 13,14 Follow-up Two weeks before a follow-up interview was due, a liaison telephoned the parent or guardian of minors to obtain their consent. If they provided consent, the liaison then contacted the youth to obtain assent and schedule their interview. The Illinois Department of Child and Family Services allowed us to recontact and interview participants who were under their guardianship, provided that we received assent from the youth. As with baseline interviews, we excluded detainees who did not wish to participate, even if their parents or guardians consented. Also as with baseline interviews, minors could still participate even if we could not reach their parent or guardian. If we could not reach them after 1 week and at least 5 attempts, we initiated the participant advocate system described above. In these cases, the liaison contacted the participant directly to request his or her assent. If we could not reach the participant by phone, an interviewer traveled to his or her location. 13,14 Clinical Research Interviewers For baseline and follow-up interviews, female participants were interviewed by female interviewers. Most interviewers had graduate degrees in psychology or an associated field and had experience interviewing at-risk youth; one-third were fluent in Spanish. All interviewers were trained for at least 1 month. Follow-up interviews were longer than baseline interviews because, at the request of our funding agencies, we added additional variables.

Methods
We searched PubMed, Google Scholar, PsychInfo, and Scopus for epidemiologic studies of firearm injury or death conducted in the United States that met the following criteria: (1) sampled youth who had been involved with the juvenile justice system; (2) published in a peerreviewed journal since 1990; and (3) reported prevalence or incidence rates of firearm injury or mortality as outcome variables. Search terms included "firearm" OR "gun", AND "death" OR "mortality" OR "injury", AND "high-risk" OR "at-risk" OR "juvenile justice" OR "detained" OR "incarcerated", AND "youth". We excluded studies that did not differentiate between deaths from firearms and those from other causes.

Data on Nonfatal Firearm Injury in the NJP Sample
At all follow-up interviews, we asked participants "since the last interview, have you had a serious physical injury you needed to take medicine for, or that required you to go to seek medical attention, or that limited your ability to do things?" If yes, we then asked "what was it?"; "gunshot wound" was one of the response options. We did not collect data on the number of firearm injuries.

Data for Firearm Mortality in Cook County
We Incarceration Incarceration variables are based on data from official records. We obtained intake and exit dates for correctional stays from the Illinois Department of Corrections adult and youth divisions, the Cook County Department of Corrections, and the Clerk of the Court of Cook County (for stays in the CCJTDC). Because it was not feasible to collect records for those in federal prisons, out-of-state prisons, and detention facilities outside of Cook County, dates for stays in these facilities are based on self-report (<3% of stays).
We matched official records to participants using names, known aliases, race and ethnicity, birth dates, and institutional ID numbers. Throughout the course of the study, we routinely updated identifying information each time a participant was contacted or interviewed. We also routinely updated institutional IDs every time a participant was interviewed in a correctional setting or discovered to be incarcerated through multiple mailings sent to participants each year of the study.

Attrition
Through December 2020, we collected data on death for all participants, regardless of whether or not they could be located for interviews. We obtained information on deaths through (1) death certificates from state medical examiners' offices; (2) online news sources; (3) the National Death Index; and (4) reports from participants' families, friends, and acquaintances. For the n = 88 participants who withdrew or refused participation, we censored them on their last interview date. We collected data on nonfatal firearm injury at every follow-up interview up through the 16-year interview. For participants who died (n = 120), withdrew (n = 88), could not be located by the 16-year interview (n = 220), or whose 16-year interview was conducted out of range (n = 13), we considered them censored for nonfatal firearm injury at their most recent interview date.
We conducted follow-up interviews at approximately 3, 5

STATISTICAL ANALYSES Poisson Models
We used Poisson regression with a log offset for time at risk to: (1) generate the incidence rates and associated 95% CIs of nonfatal firearm injury, and firearm injury and mortality, and (2) compare rates of firearm injury and mortality by sex and race and ethnicity (self-reported). We estimated incidence rates separately for males and females. As in a prior article, 15 when estimating sex and racial ethnic differences, we defined time at risk to include only days lived in the community. We excluded days incarcerated from time at risk because incarceration greatly reduces the risk of firearm injury and death; none of our participants were injured or killed by firearms while incarcerated. This approach reduces potential confounding effects of sex and race and ethnicity, because males and racial and ethnic minorities are disproportionately incarcerated. 16 Some participants reported having been injured by a firearm at more than one interview; others were injured by a firearm and, in a separate incident, killed by a firearm. For these participants, we included the first injury in our analyses of rates of firearm injury and mortality.